1
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Li N, Flanagan BA, Edmands S. The role of mitochondria in sex- and age-specific gene expression in a species without sex chromosomes. Proc Natl Acad Sci U S A 2024; 121:e2321267121. [PMID: 38838014 PMCID: PMC11181141 DOI: 10.1073/pnas.2321267121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 05/13/2024] [Indexed: 06/07/2024] Open
Abstract
Mitochondria perform an array of functions, many of which involve interactions with gene products encoded by the nucleus. These mitochondrial functions, particularly those involving energy production, can be expected to differ between sexes and across ages. Here, we measured mitochondrial effects on sex- and age-specific gene expression in parental and reciprocal F1 hybrids between allopatric populations of Tigriopus californicus with over 20% mitochondrial DNA divergence. Because the species lacks sex chromosomes, sex-biased mitochondrial effects are not confounded by the effects of sex chromosomes. Results revealed pervasive sex differences in mitochondrial effects, including effects on energetics and aging involving nuclear interactions throughout the genome. Using single-individual RNA sequencing, sex differences were found to explain more than 80% of the variance in gene expression. Males had higher expression of mitochondrial genes and mitochondrially targeted proteins (MTPs) involved in oxidative phosphorylation (OXPHOS), while females had elevated expression of non-OXPHOS MTPs, indicating strongly sex-dimorphic energy metabolism at the whole organism level. Comparison of reciprocal F1 hybrids allowed insights into the nature of mito-nuclear interactions, showing both mitochondrial effects on nuclear expression, and nuclear effects on mitochondrial expression. While based on a small set of crosses, sex-specific increases in mitochondrial expression with age were associated with longer life. Network analyses identified nuclear components of strong mito-nuclear interactions and found them to be sexually dimorphic. These results highlight the profound impact of mitochondria and mito-nuclear interactions on sex- and age-specific gene expression.
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Affiliation(s)
- Ning Li
- Department of Biological Sciences, University of Southern California, Los Angeles, CA90089
| | - Ben A. Flanagan
- Department of Biological Sciences, University of Southern California, Los Angeles, CA90089
| | - Suzanne Edmands
- Department of Biological Sciences, University of Southern California, Los Angeles, CA90089
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2
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Li N, Flanagan BA, Edmands S. The role of mitochondria in sex- and age-specific gene expression in a species without sex chromosomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.08.570893. [PMID: 38106076 PMCID: PMC10723445 DOI: 10.1101/2023.12.08.570893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Mitochondria perform an array of functions, many of which involve interactions with gene products encoded by the nucleus. These mitochondrial functions, particularly those involving energy production, can be expected to differ between sexes and across ages. Here we measured mitochondrial effects on sex- and age-specific gene expression in parental and reciprocal F1 hybrids between allopatric populations of Tigriopus californicus with over 20% mitochondrial DNA divergence. Because the species lacks sex chromosomes, sex-biased mitochondrial effects are not confounded by the effects of sex chromosomes. Using single-individual RNA sequencing, sex differences were found to explain more than 80% of the variance in gene expression. Males had higher expression of mitochondrial genes and mitochondrially targeted proteins (MTPs) involved in oxidative phosphorylation (OXPHOS), while females had elevated expression of non-OXPHOS MTPs, indicating strongly sex-dimorphic energy metabolism at the whole organism level. Comparison of reciprocal F1 hybrids allowed insights into the nature of mito-nuclear interactions, showing both mitochondrial effects on nuclear expression, as well as nuclear effects on mitochondrial expression. Across both sexes, increases in mitochondrial expression with age were associated with longer life. Network analyses identified nuclear components of strong mito-nuclear interactions, and found them to be sexually dimorphic. These results highlight the profound impact of mitochondria and mito-nuclear interactions on sex- and age-specific gene expression.
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Affiliation(s)
- Ning Li
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089, USA
| | | | - Suzanne Edmands
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089, USA
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3
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Sharma Y, Galvão AM. Maternal obesity and ovarian failure: is leptin the culprit? Anim Reprod 2023; 19:e20230007. [PMID: 36855701 PMCID: PMC9968511 DOI: 10.1590/1984-3143-ar2023-0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/24/2023] [Indexed: 02/22/2023] Open
Abstract
At the time of its discovery and characterization in 1994, leptin was mostly considered a metabolic hormone able to regulate body weight and energy homeostasis. However, in recent years, a great deal of literature has revealed leptin's pleiotropic nature, through its involvement in numerous physiological contexts including the regulation of the female reproductive tract and ovarian function. Obesity has been largely associated with infertility, and leptin signalling is known to be dysregulated in the ovaries of obese females. Hence, the disruption of ovarian leptin signalling was shown to contribute to the pathophysiology of ovarian failure in obese females, affecting transcriptional programmes in the gamete and somatic cells. This review attempts to uncover the underlying mechanisms contributing to female infertility associated with obesity, as well as to shed light on the role of leptin in the metabolic dysregulation within the follicle, the effects on the oocyte epigenome, and the potential long-term consequence to embryo programming.
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Affiliation(s)
- Yashaswi Sharma
- Institute of Animal Reproduction and Food Research of PAS, Department of Reproductive Immunology and Pathology, Olsztyn, Poland
| | - António Miguel Galvão
- Institute of Animal Reproduction and Food Research of PAS, Department of Reproductive Immunology and Pathology, Olsztyn, Poland,Babraham Institute, Epigenetics Programme, Cambridge, United Kingdom UK,Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom UK,Corresponding author: ;
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4
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Yu L, Liu M, Xu S, Wang Z, Liu T, Zhou J, Zhang D, Dong X, Pan B, Wang B, Liu S, Guo W. Follicular fluid steroid and gonadotropic hormone levels and mitochondrial function from exosomes predict embryonic development. Front Endocrinol (Lausanne) 2022; 13:1025523. [PMID: 36440207 PMCID: PMC9682035 DOI: 10.3389/fendo.2022.1025523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Human follicular fluid (FF) is a complex biological fluid that contributes to the micro-environment of oocyte development. The aim of this study was to evaluate the role of steroid and gonadotropic hormones levels and mitochondrial function in embryo development during in vitro fertilization cycles. METHODS This was a cohort study of 138 women receiving IVF/ICSI, including 136 FF samples from 109 infertile women. FF steroid and gonadotropic hormones levels were tested by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassays. The mRNA expression levels of mitochondrial electron transport chain (ETC) complex genes from FF exosomes were detected by qPCR. RESULTS Analysis of these individual FF concentrations revealed that LH and FSH concentrations were higher in follicles in which the oocyte developed into a top quality (TQ) blastocyst (LH: 9.44 ± 2.32mIU/ml, FSH: 9.32 ± 1.01mIU/ml) than those in which there was a failure of fertilization (LH: 5.30 ± 0.84mIU/ml, FSH: 6.91 ± 0.62mIU/ml). In contrast, follicular cortisone concentrations were lower for oocytes that resulted in a TQ blastocyst (12.20 ± 0.82mIU/ml). The receiver operating characteristic analysis showed that FF LH and FSH levels predicted TQ blastocyst with excellent AUC value of 0.711 and 0.747. Mitochondrial ETC complex I and III mRNA levels were increased in the FF exosomes of TQ blastocyst. Correlation analysis showed that mRNA levels of ETC complex I was positively correlated with LH and FSH levels in FF. CONCLUSION The levels of FF steroid and gonadotropic hormones from single follicle can predetermine subsequent embryo development to some extent. Furthermore, impaired exosome mitochondrial dysfunction is a potiential event that causes hormone change in embryo development.
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Affiliation(s)
- Li Yu
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Miao Liu
- Reproductive Medicine Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shiji Xu
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhenxin Wang
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Te Liu
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jiaye Zhou
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Doudou Zhang
- Reproductive Medicine Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xi Dong
- Reproductive Medicine Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Baishen Pan
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Beili Wang
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
- *Correspondence: Wei Guo, ; Suying Liu, ; Beili Wang,
| | - Suying Liu
- Reproductive Medicine Center, Zhongshan Hospital, Fudan University, Shanghai, China
- *Correspondence: Wei Guo, ; Suying Liu, ; Beili Wang,
| | - Wei Guo
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Laboratory Medicine, Xiamen Branch, Zhongshan Hospital, Fudan University, Xiamen, China
- Department of Laboratory Medicine, Wusong Branch, Zhongshan Hospital, Fudan University, Shanghai, China
- *Correspondence: Wei Guo, ; Suying Liu, ; Beili Wang,
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5
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van der Reest J, Nardini Cecchino G, Haigis MC, Kordowitzki P. Mitochondria: Their relevance during oocyte ageing. Ageing Res Rev 2021; 70:101378. [PMID: 34091076 DOI: 10.1016/j.arr.2021.101378] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/24/2021] [Accepted: 06/01/2021] [Indexed: 12/14/2022]
Abstract
The oocyte is recognised as the largest cell in mammalian species and other multicellular organisms. Mitochondria represent a high proportion of the cytoplasm in oocytes and mitochondrial architecture is different in oocytes than in somatic cells, characterised by a rounder appearance and fragmented network. Although the number of mitochondria per oocyte is higher than in any other mammalian cell, their number and activity decrease with advancing age. Mitochondria integrate numerous processes essential for cellular function, such as metabolic processes related to energy production, biosynthesis, and waste removal, as well as Ca2+ signalling and reactive oxygen species (ROS) homeostasis. Further, mitochondria are responsible for the cellular adaptation to different types of stressors such as oxidative stress or DNA damage. When these stressors outstrip the adaptive capacity of mitochondria to restore homeostasis, it leads to mitochondrial dysfunction. Decades of studies indicate that mitochondrial function is multifaceted, which is reflected in the oocyte, where mitochondria support numerous processes during oocyte maturation, fertilization, and early embryonic development. Dysregulation of mitochondrial processes has been consistently reported in ageing and age-related diseases. In this review, we describe the functions of mitochondria as bioenergetic powerhouses and signal transducers in oocytes, how dysfunction of mitochondrial processes contributes to reproductive ageing, and whether mitochondria could be targeted to promote oocyte rejuvenation.
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6
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Bettinazzi S, Milani L, Blier PU, Breton S. Bioenergetic consequences of sex-specific mitochondrial DNA evolution. Proc Biol Sci 2021; 288:20211585. [PMID: 34403637 PMCID: PMC8370797 DOI: 10.1098/rspb.2021.1585] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 07/27/2021] [Indexed: 12/16/2022] Open
Abstract
Doubly uniparental inheritance (DUI) represents a notable exception to the general rule of strict maternal inheritance (SMI) of mitochondria in metazoans. This system entails the coexistence of two mitochondrial lineages (F- and M-type) transmitted separately through oocytes and sperm, thence providing an unprecedented opportunity for the mitochondrial genome to evolve adaptively for male functions. In this study, we explored the impact of a sex-specific mitochondrial evolution upon gamete bioenergetics of DUI and SMI bivalve species, comparing the activity of key enzymes of glycolysis, fermentation, fatty acid metabolism, tricarboxylic acid cycle, oxidative phosphorylation and antioxidant metabolism. Our findings suggest reorganized bioenergetic pathways in DUI gametes compared to SMI gametes. This generally results in a decreased enzymatic capacity in DUI sperm with respect to DUI oocytes, a limitation especially prominent at the terminus of the electron transport system. This bioenergetic remodelling fits a reproductive strategy that does not require high energy input and could potentially link with the preservation of the paternally transmitted mitochondrial genome in DUI species. Whether this phenotype may derive from positive or relaxed selection acting on DUI sperm is still uncertain.
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Affiliation(s)
- Stefano Bettinazzi
- Département de sciences biologiques, Université de Montréal, Montréal, Quebec, Canada H2V 2S9
| | - Liliana Milani
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Bologna, Bologna 40126, Italia
| | - Pierre U. Blier
- Département de biologie, Université du Québec à Rimouski, Rimouski, Quebec, Canada G5 L 3A1
| | - Sophie Breton
- Département de sciences biologiques, Université de Montréal, Montréal, Quebec, Canada H2V 2S9
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7
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Colnaghi M, Pomiankowski A, Lane N. The need for high-quality oocyte mitochondria at extreme ploidy dictates mammalian germline development. eLife 2021; 10:69344. [PMID: 34279226 PMCID: PMC8337077 DOI: 10.7554/elife.69344] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/16/2021] [Indexed: 12/16/2022] Open
Abstract
Selection against deleterious mitochondrial mutations is facilitated by germline processes, lowering the risk of genetic diseases. How selection works is disputed: experimental data are conflicting and previous modeling work has not clarified the issues; here, we develop computational and evolutionary models that compare the outcome of selection at the level of individuals, cells and mitochondria. Using realistic de novo mutation rates and germline development parameters from mouse and humans, the evolutionary model predicts the observed prevalence of mitochondrial mutations and diseases in human populations. We show the importance of organelle-level selection, seen in the selective pooling of mitochondria into the Balbiani body, in achieving high-quality mitochondria at extreme ploidy in mature oocytes. Alternative mechanisms debated in the literature, bottlenecks and follicular atresia, are unlikely to account for the clinical data, because neither process effectively eliminates mitochondrial mutations under realistic conditions. Our findings explain the major features of female germline architecture, notably the longstanding paradox of over-proliferation of primordial germ cells followed by massive loss. The near-universality of these processes across animal taxa makes sense in light of the need to maintain mitochondrial quality at extreme ploidy in mature oocytes, in the absence of sex and recombination.
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Affiliation(s)
- Marco Colnaghi
- CoMPLEX, University College London, London, United Kingdom.,Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Andrew Pomiankowski
- CoMPLEX, University College London, London, United Kingdom.,Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Nick Lane
- CoMPLEX, University College London, London, United Kingdom.,Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
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8
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Hörandl E, Hadacek F. Oxygen, life forms, and the evolution of sexes in multicellular eukaryotes. Heredity (Edinb) 2020; 125:1-14. [PMID: 32415185 PMCID: PMC7413252 DOI: 10.1038/s41437-020-0317-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 04/26/2020] [Accepted: 04/26/2020] [Indexed: 12/27/2022] Open
Abstract
The evolutionary advantage of different sexual systems in multicellular eukaryotes is still not well understood, because the differentiation into male and female individuals halves offspring production compared with asexuality. Here we propose that various physiological adaptations to oxidative stress could have forged sessility versus motility, and consequently the evolution of sexual systems in multicellular animals, plants, and fungi. Photosynthesis causes substantial amounts of oxidative stress in photoautotrophic plants and, likewise, oxidative chemistry of polymer breakdown, cellulose and lignin, for saprotrophic fungi. In both cases, its extent precludes motility, an additional source of oxidative stress. Sessile life form and the lack of neuronal systems, however, limit options for mate recognition and adult sexual selection, resulting in inefficient mate-searching systems. Hence, sessility requires that all individuals can produce offspring, which is achieved by hermaphroditism in plants and/or by multiple mating types in fungi. In animals, motility requires neuronal systems, and muscle activity, both of which are highly sensitive to oxidative damage. As a consequence, motility has evolved in animals as heterotrophic organisms that (1) are not photosynthetically active, and (2) are not primary decomposers. Adaptations to motility provide prerequisites for an active mating behavior and efficient mate-searching systems. These benefits compensate for the "cost of males", and may explain the early evolution of sex chromosomes in metazoans. We conclude that different sexual systems evolved under the indirect physiological constraints of lifestyles.
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Affiliation(s)
- Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants, University of Goettingen, Göttingen, Germany.
| | - Franz Hadacek
- Department of Plant Biochemistry, University of Goettingen, Göttingen, Germany
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9
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Ganesh S, Horvat F, Drutovic D, Efenberkova M, Pinkas D, Jindrova A, Pasulka J, Iyyappan R, Malik R, Susor A, Vlahovicek K, Solc P, Svoboda P. The most abundant maternal lncRNA Sirena1 acts post-transcriptionally and impacts mitochondrial distribution. Nucleic Acids Res 2020; 48:3211-3227. [PMID: 31956907 PMCID: PMC7102984 DOI: 10.1093/nar/gkz1239] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/10/2019] [Accepted: 01/02/2020] [Indexed: 12/13/2022] Open
Abstract
Tens of thousands of rapidly evolving long non-coding RNA (lncRNA) genes have been identified, but functions were assigned to relatively few of them. The lncRNA contribution to the mouse oocyte physiology remains unknown. We report the evolutionary history and functional analysis of Sirena1, the most expressed lncRNA and the 10th most abundant poly(A) transcript in mouse oocytes. Sirena1 appeared in the common ancestor of mouse and rat and became engaged in two different post-transcriptional regulations. First, antisense oriented Elob pseudogene insertion into Sirena1 exon 1 is a source of small RNAs targeting Elob mRNA via RNA interference. Second, Sirena1 evolved functional cytoplasmic polyadenylation elements, an unexpected feature borrowed from translation control of specific maternal mRNAs. Sirena1 knock-out does not affect fertility, but causes minor dysregulation of the maternal transcriptome. This includes increased levels of Elob and mitochondrial mRNAs. Mitochondria in Sirena1−/− oocytes disperse from the perinuclear compartment, but do not change in number or ultrastructure. Taken together, Sirena1 contributes to RNA interference and mitochondrial aggregation in mouse oocytes. Sirena1 exemplifies how lncRNAs stochastically engage or even repurpose molecular mechanisms during evolution. Simultaneously, Sirena1 expression levels and unique functional features contrast with the lack of functional importance assessed under laboratory conditions.
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Affiliation(s)
- Sravya Ganesh
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Filip Horvat
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Bioinformatics Group, Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Croatia
| | - David Drutovic
- Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Libechov, Czech Republic
| | - Michaela Efenberkova
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dominik Pinkas
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Anna Jindrova
- Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Libechov, Czech Republic
| | - Josef Pasulka
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Rajan Iyyappan
- Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Libechov, Czech Republic
| | - Radek Malik
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Andrej Susor
- Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Libechov, Czech Republic
| | - Kristian Vlahovicek
- Bioinformatics Group, Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Croatia
| | - Petr Solc
- Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Libechov, Czech Republic
| | - Petr Svoboda
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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10
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Knorre DA. Intracellular quality control of mitochondrial DNA: evidence and limitations. Philos Trans R Soc Lond B Biol Sci 2019; 375:20190176. [PMID: 31787047 DOI: 10.1098/rstb.2019.0176] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic cells can harbour mitochondria with markedly different transmembrane potentials. Intracellular mitochondrial quality-control mechanisms (e.g. mitophagy) rely on this intracellular variation to distinguish functional and damaged (depolarized) mitochondria. Given that intracellular mitochondrial DNA (mtDNA) genetic variation can induce mitochondrial heterogeneity, mitophagy could remove deleterious mtDNA variants in cells. However, the reliance of mitophagy on the mitochondrial transmembrane potential suggests that mtDNAs with deleterious mutations in ATP synthase can evade the control. This evasion is possible because inhibition of ATP synthase can increase the mitochondrial transmembrane potential. Moreover, the linkage of the mtDNA genotype to individual mitochondrial performance is expected to be weak owing to intracellular mitochondrial intercomplementation. Nonetheless, I reason that intracellular mtDNA quality control is possible and crucial at the zygote stage of the life cycle. Indeed, species with biparental mtDNA inheritance or frequent 'leakage' of paternal mtDNA can be vulnerable to invasion of selfish mtDNAs at the stage of gamete fusion. Here, I critically review recent findings on intracellular mtDNA quality control by mitophagy and discuss other mechanisms by which the nuclear genome can affect the competition of mtDNA variants in the cell. This article is part of the theme issue 'Linking the mitochondrial genotype to phenotype: a complex endeavour'.
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Affiliation(s)
- Dmitry A Knorre
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Leninskiye Gory 1-40, Moscow 119991, Russia.,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Trubetskaya Str. 8-2, Moscow 119991, Russia
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11
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Qi L, Chen X, Wang J, Lv B, Zhang J, Ni B, Xue Z. Mitochondria: the panacea to improve oocyte quality? ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:789. [PMID: 32042805 DOI: 10.21037/atm.2019.12.02] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Oocyte quality is one of the most important factors involving in female reproduction. The number of compromised oocytes will increase with maternal age, while mitochondrial dysfunction has implicated in age-related poor oocyte. Together with the successful application of ooplasmic transfer (OT) and the critical role of mitochondria in the oocyte, functional mitochondria transfer may be a feasible strategy to improve oocyte quality. However, limitation on ethics and laws are strictly and optimal condition or methods to exert transferring need to be further explored. Therefore, the role of oocyte mitochondria and the effective molecular involving in oocyte quality will be hot topics in next few years. In this review, we summarize the potential mechanism of mitochondria in oocyte and embryo development and discuss the next step for mitochondrial transfer therapy.
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Affiliation(s)
- Lingbin Qi
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, China
| | - Xian Chen
- Shenzhen Key Laboratory for Reproductive Immunology of Peri-implantation, Shenzhen Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, Shenzhen 518045, China
| | - Jian Wang
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, China
| | - Bo Lv
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, China
| | - Junhui Zhang
- Reproductive Medical Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei 230032, China
| | - Bin Ni
- NHC Key Laboratory of Birth Defect for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha 410008, China
| | - Zhigang Xue
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200092, China.,Reproductive Medicine Center, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China
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12
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Abstract
Idiopathic pulmonary fibrosis (IPF) is an extremely aggressive lung disease that develops almost exclusively in older individuals, carries a very poor prognosis, and lacks any truly effective therapies. The current conceptual model is that IPF develops because of an age-related decline in the ability of the lung epithelium to regenerate after injury, largely due to death or senescence of epithelial progenitor cells in the distal airways. This loss of regenerative capacity is thought to initiate a chronic and ineffective wound-healing response, characterized by persistent, low-grade lung inflammation and sustained production of collagen and other extracellular matrix materials. Despite recent advances in our understanding of IPF pathobiology, there remains a pressing need to further delineate underlying mechanisms to develop more effective therapies for this disease. In this review, we build the case that many of the manifestations of IPF result from a failure of cells to effectively manage their proteome. We propose that epithelial progenitor cells, as well as immune cells and fibroblasts, become functionally impaired, at least in part, because of an accumulation or a loss in the expression of various crucial proteins. Further, we propose that central to this defect is the dysregulation of the ubiquitin-proteasome system (UPS), which is the major protein-degradation system in eukaryotic cells. Lastly, borrowing concepts from other fields, we discuss how targeting the UPS system could be employed as a novel treatment for IPF and perhaps for other fibrotic lung diseases as well.
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Affiliation(s)
- Willy Roque
- Center for Translational Medicine and Jane and Leonard Korman Lung Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ross Summer
- Center for Translational Medicine and Jane and Leonard Korman Lung Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Freddy Romero
- Center for Translational Medicine and Jane and Leonard Korman Lung Center, Thomas Jefferson University, Philadelphia, PA, USA
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13
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Kramer P, Bressan P. Mitochondria Inspire a Lifestyle. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2019; 231:105-126. [PMID: 30610376 DOI: 10.1007/102_2018_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Tucked inside our cells, we animals (and plants, and fungi) carry mitochondria, minuscule descendants of bacteria that invaded our common ancestor 2 billion years ago. This unplanned breakthrough endowed our ancestors with a convenient, portable source of energy, enabling them to progress towards more ambitious forms of life. Mitochondria still manufacture most of our energy; we have evolved to invest it to grow and produce offspring, and to last long enough to make it all happen. Yet because the continuous generation of energy is inevitably linked to that of toxic free radicals, mitochondria give us life and give us death. Stripping away clutter and minutiae, here we present a big-picture perspective of how mitochondria work, how they are passed on virtually only by mothers, and how they shape the lifestyles of species and individuals. We discuss why restricting food prolongs lifespan, why reproducing shortens it, and why moving about protects us from free radicals despite increasing their production. We show that our immune cells use special mitochondria to keep control over our gut microbes. And we lay out how the fabrication of energy and free radicals sets the internal clocks that command our everyday rhythms-waking, eating, sleeping. Mitochondria run the show.
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Affiliation(s)
- Peter Kramer
- Dipartimento di Psicologia Generale, University of Padova, Padova, Italy
| | - Paola Bressan
- Dipartimento di Psicologia Generale, University of Padova, Padova, Italy.
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14
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Marelja Z, Leimkühler S, Missirlis F. Iron Sulfur and Molybdenum Cofactor Enzymes Regulate the Drosophila Life Cycle by Controlling Cell Metabolism. Front Physiol 2018; 9:50. [PMID: 29491838 PMCID: PMC5817353 DOI: 10.3389/fphys.2018.00050] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/16/2018] [Indexed: 12/20/2022] Open
Abstract
Iron sulfur (Fe-S) clusters and the molybdenum cofactor (Moco) are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i) mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii) increased iron transiently displaces manganese on superoxide dismutase, which may function as a mitochondrial iron sensor since it is inactivated by iron; (iii) with the Krebs cycle thus disrupted, citrate is exported to the cytosol for fatty acid synthesis, while succinyl-CoA and the iron are used for heme biosynthesis; (iv) as iron is used for heme biosynthesis its concentration in the matrix drops allowing for manganese to reactivate superoxide dismutase and Fe-S cluster biosynthesis to reestablish the Krebs cycle.
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Affiliation(s)
- Zvonimir Marelja
- Imagine Institute, Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Silke Leimkühler
- Department of Molecular Enzymology, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Fanis Missirlis
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
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15
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Abstract
Most of the energy we get to spend is furnished by mitochondria, minuscule living structures sitting inside our cells or dispatched back and forth within them to where they are needed. Mitochondria produce energy by burning down what remains of our meal after we have digested it, but at the cost of constantly corroding themselves and us. Here we review how our mitochondria evolved from invading bacteria and have retained a small amount of independence from us; how we inherit them only from our mother; and how they are heavily implicated in learning, memory, cognition, and virtually every mental or neurological affliction. We discuss why counteracting mitochondrial corrosion with antioxidant supplements is often unwise, and why our mitochondria, and therefore we ourselves, benefit instead from exercise, meditation, sleep, sunshine, and particular eating habits. Finally, we describe how malfunctioning mitochondria force rats to become socially subordinate to others, how such disparity can be evened off by a vitamin, and why these findings are relevant to us.
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Affiliation(s)
- Peter Kramer
- Department of General Psychology, University of Padua, Italy
| | - Paola Bressan
- Department of General Psychology, University of Padua, Italy
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16
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Why humans develop sex cells as embryos — but corals don't. Nature 2016. [DOI: 10.1038/nature.2016.21218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Radzvilavicius AL, Hadjivasiliou Z, Pomiankowski A, Lane N. Selection for Mitochondrial Quality Drives Evolution of the Germline. PLoS Biol 2016; 14:e2000410. [PMID: 27997535 PMCID: PMC5172535 DOI: 10.1371/journal.pbio.2000410] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 11/29/2016] [Indexed: 12/31/2022] Open
Abstract
The origin of the germline-soma distinction is a fundamental unsolved question. Plants and basal metazoans do not have a germline but generate gametes from pluripotent stem cells in somatic tissues (somatic gametogenesis). In contrast, most bilaterians sequester a dedicated germline early in development. We develop an evolutionary model which shows that selection for mitochondrial quality drives germline evolution. In organisms with low mitochondrial replication error rates, segregation of mutations over multiple cell divisions generates variation, allowing selection to optimize gamete quality through somatic gametogenesis. Higher mutation rates promote early germline sequestration. We also consider how oogamy (a large female gamete packed with mitochondria) alters selection on the germline. Oogamy is beneficial as it reduces mitochondrial segregation in early development, improving adult fitness by restricting variation between tissues. But it also limits variation between early-sequestered oocytes, undermining gamete quality. Oocyte variation is restored through proliferation of germline cells, producing more germ cells than strictly needed, explaining the random culling (atresia) of precursor cells in bilaterians. Unlike other models of germline evolution, selection for mitochondrial quality can explain the stability of somatic gametogenesis in plants and basal metazoans, the evolution of oogamy in all plants and animals with tissue differentiation, and the mutational forces driving early germline sequestration in active bilaterians. The origins of predation in motile bilaterians in the Cambrian explosion is likely to have increased rates of tissue turnover and mitochondrial replication errors, in turn driving germline evolution and the emergence of complex developmental processes.
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Affiliation(s)
- Arunas L. Radzvilavicius
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, London, United Kingdom
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Zena Hadjivasiliou
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, London, United Kingdom
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Andrew Pomiankowski
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, London, United Kingdom
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Nick Lane
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, London, United Kingdom
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
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18
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Misas E, Muñoz JF, Gallo JE, McEwen JG, Clay OK. From NGS assembly challenges to instability of fungal mitochondrial genomes: A case study in genome complexity. Comput Biol Chem 2016; 61:258-69. [PMID: 26970210 DOI: 10.1016/j.compbiolchem.2016.02.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 02/03/2016] [Accepted: 02/16/2016] [Indexed: 01/26/2023]
Abstract
The presence of repetitive or non-unique DNA persisting over sizable regions of a eukaryotic genome can hinder the genome's successful de novo assembly from short reads: ambiguities in assigning genome locations to the non-unique subsequences can result in premature termination of contigs and thus overfragmented assemblies. Fungal mitochondrial (mtDNA) genomes are compact (typically less than 100 kb), yet often contain short non-unique sequences that can be shown to impede their successful de novo assembly in silico. Such repeats can also confuse processes in the cell in vivo. A well-studied example is ectopic (out-of-register, illegitimate) recombination associated with repeat pairs, which can lead to deletion of functionally important genes that are located between the repeats. Repeats that remain conserved over micro- or macroevolutionary timescales despite such risks may indicate functionally or structurally (e.g., for replication) important regions. This principle could form the basis of a mining strategy for accelerating discovery of function in genome sequences. We present here our screening of a sample of 11 fully sequenced fungal mitochondrial genomes by observing where exact k-mer repeats occurred several times; initial analyses motivated us to focus on 17-mers occurring more than three times. Based on the diverse repeats we observe, we propose that such screening may serve as an efficient expedient for gaining a rapid but representative first insight into the repeat landscapes of sparsely characterized mitochondrial chromosomes. Our matching of the flagged repeats to previously reported regions of interest supports the idea that systems of persisting, non-trivial repeats in genomes can often highlight features meriting further attention.
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Affiliation(s)
- Elizabeth Misas
- Cellular & Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia; Institute of Biology, Universidad de Antioquia, Medellín, Colombia
| | - José Fernando Muñoz
- Cellular & Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia; Institute of Biology, Universidad de Antioquia, Medellín, Colombia
| | - Juan Esteban Gallo
- Cellular & Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia; Doctoral Program in Biomedical Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Juan Guillermo McEwen
- Cellular & Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia; School of Medicine, Universidad de Antioquia, Medellín, Colombia
| | - Oliver Keatinge Clay
- Cellular & Molecular Biology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia; School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia.
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19
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Abstract
PURPOSE OF REVIEW Mitochondria are cellular organelles that are required for energy production. Emerging evidence demonstrates their role in oocyte development and reproduction. In this review, we examine recent animal and clinical studies on the role of mitochondria in fertility. We also analyse the impact of assisted reproductive techniques (ARTs) on mitochondrial function and discuss the future clinical implications of mitochondrial nutrients and mitochondrial replacement. RECENT FINDINGS Mitochondria affect all aspects of mammalian reproduction. They are essential for optimal oocyte maturation, fertilization and embryonic development. Mitochondrial dysfunction causes a decrease in oocyte quality and interferes with embryonic development. ART procedures affect mitochondrial function, while mitochondrial nutrients may increase mitochondrial performance in oocytes. New mitochondrial replacement procedures using mitochondria obtained from polar bodies or from the patient's own oogonial stem cells are promising and may address concerns related to the induction of high-levels of heteroplasmy, which could potentially result in negative long-term health effects. SUMMARY Optimal energy production is required for oocyte and embryo development, and mitochondrial abnormalities have devastating reproductive consequences. Improvement of oocyte mitochondrial function via intake of compounds that boost mitochondrial activity may have clinical benefits, and mitochondrial replacement could potentially be used for the prevention of mitochondrial diseases.
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Affiliation(s)
- Elnur Babayev
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut, USA
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20
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Milani L, Ghiselli F. Mitochondrial activity in gametes and transmission of viable mtDNA. Biol Direct 2015; 10:22. [PMID: 25981894 PMCID: PMC4435915 DOI: 10.1186/s13062-015-0057-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 04/29/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The retention of a genome in mitochondria (mtDNA) has several consequences, among which the problem of ensuring a faithful transmission of its genetic information through generations despite the accumulation of oxidative damage by reactive oxygen species (ROS) predicted by the free radical theory of ageing. A division of labour between male and female germ line mitochondria was proposed: since mtDNA is maternally inherited, female gametes would prevent damages by repressing oxidative phosphorylation, thus being quiescent genetic templates. We assessed mitochondrial activity in gametes of an unusual biological system (doubly uniparental inheritance of mitochondria, DUI), in which also sperm mtDNA is transmitted to the progeny, thus having to overcome the problem of maintaining genetic information viability while producing ATP for swimming. RESULTS Ultrastructural analysis shows no difference in the conformation of mitochondrial cristae in male and female mature gametes, while mitochondria in immature oocytes exhibit a simpler internal structure. Our data on transcriptional activity in germ line mitochondria show variability between sexes and different developmental stages, but we do not find evidence for transcriptional quiescence of mitochondria. Our observations on mitochondrial membrane potential are consistent with mitochondria being active in both male and female gametes. CONCLUSIONS Our findings and the literature we discussed may be consistent with the hypothesis that template mitochondria are not functionally silenced, on the contrary their activity might be fundamental for the inheritance mechanism. We think that during gametogenesis, fertilization and embryo development, mitochondria undergo selection for different traits (e.g. replication, membrane potential), increasing the probability of the transmission of functional organelles. In these phases of life cycle, the great reduction in mtDNA copy number per organelle/cell and the stochastic segregation of mtDNA variants would greatly improve the efficiency of selection. When a higher mtDNA copy number per organelle/cell is present, selection on mtDNA deleterious mutants is less effective, due to the buffering effect of wild-type variants. In our opinion, a combination of drift and selection on germ line mtDNA population, might be responsible for the maintenance of viable mitochondrial genetic information through generations, and a mitochondrial activity would be necessary for the selective process.
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Affiliation(s)
- Liliana Milani
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali, Università di Bologna, Via Selmi 3, 40126, Bologna, Italy.
| | - Fabrizio Ghiselli
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali, Università di Bologna, Via Selmi 3, 40126, Bologna, Italy.
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21
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Abstract
Why the DNA-containing organelles, chloroplasts, and mitochondria, are inherited maternally is a long standing and unsolved question. However, recent years have seen a paradigm shift, in that the absoluteness of uniparental inheritance is increasingly questioned. Here, we review the field and propose a unifying model for organelle inheritance. We argue that the predominance of the maternal mode is a result of higher mutational load in the paternal gamete. Uniparental inheritance evolved from relaxed organelle inheritance patterns because it avoids the spread of selfish cytoplasmic elements. However, on evolutionary timescales, uniparentally inherited organelles are susceptible to mutational meltdown (Muller's ratchet). To prevent this, fall-back to relaxed inheritance patterns occurs, allowing low levels of sexual organelle recombination. Since sexual organelle recombination is insufficient to mitigate the effects of selfish cytoplasmic elements, various mechanisms for uniparental inheritance then evolve again independently. Organelle inheritance must therefore be seen as an evolutionary unstable trait, with a strong general bias to the uniparental, maternal, mode.
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Affiliation(s)
- Stephan Greiner
- Max-Planck-Institut für Molekulare PflanzenphysiologiePotsdam-Golm, Germany
| | - Johanna Sobanski
- Max-Planck-Institut für Molekulare PflanzenphysiologiePotsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare PflanzenphysiologiePotsdam-Golm, Germany
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22
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de Paula WBM, Agip ANA, Missirlis F, Ashworth R, Vizcay-Barrena G, Lucas CH, Allen JF. Female and male gamete mitochondria are distinct and complementary in transcription, structure, and genome function. Genome Biol Evol 2014; 5:1969-77. [PMID: 24068653 PMCID: PMC3814205 DOI: 10.1093/gbe/evt147] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Respiratory electron transport in mitochondria is coupled to ATP synthesis while generating mutagenic oxygen free radicals. Mitochondrial DNA mutation then accumulates with age, and may set a limit to the lifespan of individual, multicellular organisms. Why is this mutation not inherited? Here we demonstrate that female gametes—oocytes—have unusually small and simple mitochondria that are suppressed for DNA transcription, electron transport, and free radical production. By contrast, male gametes—sperm—and somatic cells of both sexes transcribe mitochondrial genes for respiratory electron carriers and produce oxygen free radicals. This germ-line division between mitochondria of sperm and egg is observed in both the vinegar fruitfly and the zebrafish—species spanning a major evolutionary divide within the animal kingdom. We interpret these findings as an evidence that oocyte mitochondria serve primarily as genetic templates, giving rise, irreversibly and in each new generation, to the familiar energy-transducing mitochondria of somatic cells and male gametes. Suppressed mitochondrial metabolism in the female germ line may therefore constitute a mechanism for increasing the fidelity of mitochondrial DNA inheritance.
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Affiliation(s)
- Wilson B M de Paula
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
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